Corrugated galvanised iron or steel (CGI) is a building material composed of sheets of hot-dip galvanised mild steel, cold-rolled to produce a linear corrugated pattern in them. The corrugations increase the bending strength of the sheet in the direction perpendicular to the corrugations, but not parallel to them. Normally each sheet is manufactured longer in its strong direction.
CGI is lightweight and easily transported.
Copper offers a unique character and durability as a roofing material. Its appearance can complement any style of building, from traditional to modern. Its warmth and beauty make it a desirable material for many architects. Copper also satisfies demands of architects and building owners regarding lifetime cost, ease of fabrication, low maintenance, and environmental friendliness.
New copper roof installation.
The installation of copper roofing is a craft requiring experienced installers. Its ductility and malleability make it a compatible material to form over irregular roof structures. It is easy to hammer or work into watertight designs without caulk or gaskets. Domes and other curved roof shapes are readily handled with copper.